Augustin sentex



UNITED STATES PATENT OFFICE.

AUGUSTIN SENTEX, CONSTANTIN MARECHAL, AND ALFRED SAUNIER, OF PARIS,FRANCE.

PROCESS OF MAKING BRONZE ALLOYS.

SPECIFICATION forming part of Letters Patent No. 418,424, dated December,31, 1889.

Application filed March 9, 1888. Serial No. 266,724. (No specimens.)Patented in Belgium September 26, 1887, No. 78,999 in France February 1,1888, No. 188,473; in England February 8, 1888,1510. 1,886; in ItalyFehruary18, 1888, XLV, 364, and

p in Germany February 15, 1889, No. 46,580.

To all whom it may concern:

Be it known that we, AUGUSTIN SENTEX, CONSTANTIN MAREOHAL, and ALFREDSAU- NIER, all of Paris, in the Republic of France, have invented anImprovement in Processes of Making Bronze Alloys, (for which we haveobtained Letters Patent in France for fifteen years, dated February1,1888,No. 188,478; in Belgium, September 26, 1887, No. 78,999; inEngland February 8, 1888, No. 1,886; in Italy February 18, 1888, Vol.XLV, No. 364, and in Germany February 15, 1889, No. 46,580;) and we dohereby declare that the following is a full and exact descriptionthereof.

I-Ieretofore bronze containing a large proportion of tin has been onlypartially malleable. It cracks in rolling, splits in theheating-furnace, and plates or flakes of tin often appear at the surfaceof plates made from such material. These defects are caused by the wantof homogeneity due to the tendency of the tin to separate from thecopper when in the fused state. They have been overcome in sandcastings-such as bells, guns, bearings, and so forth-by the addition ofone or two per cent. of phosphorus, which imparts hardness andhomogeneity to the metal and serves as a bond or solder for the metalscomprising the bronze; bnt bronze made in that way is always brittle andunsuitable for being rolled or drawn into Wire.

By the process forming the subject of the present invention malleableand ductile bronze can be produced containing a large proportion of tin.This result is effected by submitting the alloys as well as the metalscomposing them to a series of chemical operations which completelymodify their properties.

' Although the proportions of the metalscomposing the alloy may varyconsiderably according to the properties it is desired to impart to thealloy-such as malleability, ductility, tenacity, hardness, sonorosity,&c-the process remains the same unless the metal is not required tofulfill certain conditions such as inoxidizability, for example, in

which case one or more of the operations may be omitted.

By way of example I will now proceed to describe the manufacture ofbronze of as perfeet a quality as possible and composed of about tenkilograms of copper to one and onef into a crucible and the temperatureraised to the melting-point. At that moment fifty grams of a mixture ofequal parts of nitrate of potash and of cyanide of potassium are to beadded for the double purpose of reducing the oxides and of enlarging thegrain of the metal. twenty-five grams of bitartrate of potash mixed withan equal quantity of cyanide of potassium are to be introduced for thesame purpose. The tin, prepared and purified as above described, is thenadded to the copper after poling or stirring with green wood. At thatmoment fifty grams of a mixture of equal parts of sal-ammonia orhydrochlorate of ammonia and of cyanide of potassium are introduced intothe crucible, then an instant after one gram of phosphuret of copper toimpart mildness' to the metal, and about twenty grams of Marseillessoap, consisting, substantially, of fifty parts of olive-oil, five partsof potash or soda, and forty-five parts of water, which fattens themetal still more. Finally, at the moment of running the liquid metal,after poling or stirring with green wood, a gram of sodium isintroduced, which alloys with the mass, further reducing the oxides, andby its affinity for the tin, sal-ammoniac, and other products rendersthe alloy inoxidizable. This inoxidizability increases as the proportionof tin increases. The quantity of phosphorus and sodium may be increasedif the proportion of tin be reduced.

Bars or plates of bronze cast in this manner are entirely free fromcracks and blow- After complete fusion of the copper,

holes, and if prepared in the ordinary way they maybe rolled and drawnwith the greatest ease. The metal obtained has the appearance andsonorosity of gold and resists all atmospheric action.

The same metal when cast in sand and which iii that case may be richerin tin, gives fine castings which, when pickled, resist oxidation aswell as the alloys of gold.

The process of manufacturing bronze,whicl1 consists in preydouslypurifying the tin by adding thereto while it is in a state of tusion asuitable proportion of niter and then letting it cool, in melting thecopper and maintaining it in a state of fusion and adding theretonitrate of potash and cyanide of potassium, in adding to the copper thusprepared the previously-purified tin, then introducing into the fusedalloy sal-ammoniac or hydrochlorate of ammonia, cyanide of potassium,phosphurct of copper, and Marseilles soap, in adding sodium after polingor stirring with green wood, and finally in casting the metal so treatedinto the required shape, as hereinbefore described.

AUGUSTIN SEN TEX. CONSTANTIN MAREOHAL. ALFRED SAUNIER. Vi tn esses:

RoBT. M. HOOPER, ALPHONSE BLEBUT.

